25 Information is often transmitted using fiber optic cables. Fiber optic cables are made from a glass fiber surrounded by cladding material with an optical refractive index less than that of the glass fiber. An outer covering protects the cladding from exterior damage. Light is transmitted into the cable, in pulses, so that it is incident on the glass fiber-cladding boundary at an angle 8, as shown in the figure below. The pulses of light undergo total internal reflection. - e e Outer cOVET _______'.____._._.--'"_'__ Cladding n = 1.45 Glass Fibre n = 1.47 Cladding n = 1.45 _ Outer cover a. Calculate the speed of light in the glass fiber and cladding. b. Determine the minimum value of 6, i.e. critical angle, that will allow total internal reflection of the pulses of light to occur. c. Calculate the time it would take a pulse of light to travel along 1.0 km cable at this critical angle. d. How does the time calculated in part c compare to the time it would take the light to travel along the glass fiber at 1.0 km cable if the B is 90